A United Airlines flight from Houston to San Francisco had to be diverted to Albuquerque, New Mexico, after the co-pilot passed out.

Albuquerque airport spokesman Dan Jiron said air traffic controllers got word shortly after 8 a.m. Tuesday that the plane would be landing after the first officer, who is second in command, had a medical episode. The plane landed without incident around 8:20 a.m.

Jiron said the co-pilot regained consciousness and was able to walk off the plane to be transported to a hospital. The airport had no details about the co-pilot’s condition or what may have caused the episode.